Tubing blowout preventer



April 28, 1970 M. L. CROW ETAL TUBlNG BLOWOUT PREVENTER 2 Sheets-Sheet 1Original Filed May 13, 1965 INVENTORS Morgan L.Cr0w Frederick Lee AdamsATTORNEY A ril 28, 1970 M. CROW mm. 3, 08,

TUBING BLOWOUT PREVENTER Original Filed May 13, 1965 2 Sheets-Sheet 2INVENTORS Morgan L. Crow ri m Frederick Lee Adams ATTORNEY United StatesPatent "ice U.S. Cl. 277-75 2 Claims ABSTRACT OF THE DISCLOSURE Ablowout preventer for use in oil and gas wells that has a hollow bodywith a vertical bore and coinciding lateral bores communicating with thevertical bore. In each lateral bore, there is a ram assembly and a sea]assembly.

In one form of the invention, the ram assembly, for moving the sealassembly relative to the vertical bore, has an end plate slidable withinthe lateral bore and has a feed screw housing also slidable within thelateral bore with an outer elongated threaded end extending freelythrough the end plate. The feed screw housing is positioned within thelateral bore intermediate the end plate and the back plate. A feed screwis attached rotatably to the back plate and extends through the feedscrew housing and its outer elongated end. A yoke element is droppedthrough an opening in the housing defining the lateral bore to lock theend plate in place so that by tightening a nut on the outer elongatedthreaded end of the feed screw housing, the feed screw housing and theend plate are drawn together to compress a packing therebetween intosealing engagement with the lateral bore.

Each seal assembly includes a top plate and a lower plate positioned onopposite sides of a resilient sealing element. A pin extends through theback plate of the ram assembly and attaches the top plate thereto. Asimilar pin attaches the lower plate to the back plate, so that both thetop plate and the lower plate are moveable relative to the sealingelement.

This application is a division of application Ser. No. 455,451, filedMay 13, 1965, now Patent No. 3,399,901 granted Sept. 3, 1968.

This invention is concerned with a blowout preventer to be installed ona well head to confine pressure in the well, and is particularlyconcerned with a blowout preventer intended to be installed on thetubing head at the top of the well, and is arranged to provide a sealabout a tubing string, a polished rod, wire line, or a like memberextending therethrough; or it may be provided with solid rams thereinwhich will close off the passage above the tubing head.

The blowout preventer hereinafter described and claimed is particularlydesigned for use in high temperature treatment of wells such as steaminjection down hole heater procedure, and in high temperature productioninstallations wherein both the pressure and temperature to be confinedare unusually high.

Means are provided to permit well pressure to communicate with the rearsides of the ram sealing members with the rams closed in order to allowthe well pressure to assist in making the seal, to increase the sealingeffect proportional to the increase in pressure from below, or tocompensate for wear and deterioration of the seals on the rams.

It is, therefore, a primary object of the invention to provide a blowoutpreventer wherein the pressure in the well therebelow is allowed tocommunicate with the area 3,508,759 Patented Apr. 28, 1970 behind therams while the rams are in sealing position to thereby permit the Wellpressure to assist in maintaining a tight sea] by the ram sealingelements.

Still another object of the invention is to provide in a tubing blowoutpreventer means whereby the rams are not sealed about their outsidediameter until they are in closed position thereby facilitating themovement of the rams into closed position.

Still another object of the invention is to provide in a tubing blowoutpreventer a ram assembly wherein the upper and lower support platesthereof are permitted to move longitudinally with reference to thesealing material while the ram is being moved to closed position tothereby permit constantly applied compressive sealing force on the ramsealing material while being moved to closed position.

Another object of the invention is to provide in a tubing blowoutpreventer ram sealing assemblies which are easily removed anddisassembled to permit the ram sealing element to be quickly and easilyreplaced.

A still further object of the invention is to provide in a tubingblowout preventer means for quickly and easily removing the ramassemblies and feed screws therefor to permit the changing of ramsealing assemblies and elements.

A general object of the invention is to provide a relativelyinexpensive, easily operable and easily serviceable, yet highlyeffective, blowout preventer, which will confine extremely highpressures encountered in steam injection, downhole heater and hightemperature production installations, as well as pressure in wellswherein high bottom hole pressure is encountered.

Other and further objects of the invention will become apparent uponreading the detailed specification hereinafter following and byreferring to the drawings annexed hereto.

A suitable embodiment of the invention is shown in the attached drawingswherein,

FIGURE I is a half-sectional elevational view of the blowout preventerassembly as it would appear when attached to the well head, and whereinthe rams are in sealing position about a polished rod,

FIGURE II is a perspective exploded view of one form of the ram sealingassembly which includes the ram sealing element and the upper and lowersupport plates therefor,

FIGURE III is an end elevational view of the upper support plate for theram sealing assembly,

FIGURE IV is a cross-sectional elevational view taken along the lineIVIV of FIGURE III,

FIGURE V is a front end elevational view of the ram sealing element;

FIGURE VI is a side elevational view of the ram sealing element;

FIGURE VII is an end elevational view of the bottom support plate forthe ram sealing assembly;

FIGURE VIII is a cross-sectional elevational view taken along the lineVIIIVIII of FIGURE VII, and

FIGURE IX is an inner end elevational view of the back support plate forthe ram sealing assembly.

Numeral references are employed to indicate the various parts shown inthe drawings and like numerals indicate like parts throughout thevarious figures of the drawings.

Referring to the drawings, the numeral 1 indicates a hollow body havinga vertical bore 1a therethrough.

Coinciding laterally extending, hollow, cylindrically shaped portions 2and 3 are a part of, and extend from the body 1, providing alignedcircular passages right angularly intersecting the bore 1a. The body 1also includes hollow cylindrical neck portions 4 and 5 to which areconnected the upper flange 6 and the lower flange 13.

A sealing flange 7 is secured to the upper flange 6 by means of threadedstuds 11 which extend through coinciding passages in the flanges 6 and 7and are secured thereto by means of nuts 9 and 10.

A sealing ring 8 is compressed in coinciding grooves 8a and 8b in theopposed faces of the flanges 6 and 7, to provide a seal therebetween.

A section of pipe 12, which may communicate with surface equipment (notshown), is threadedly engaged at 12a to the sealing flange 7.

A flange 14, which may be a sealing flange, or which may be a flange atthe upper end of a tubing head, is secured to the lower flange 13 bymeans of threaded studs 15 which are secured thereto by means of nuts16.

A sealing ring 13a is pressed between coinciding grooves 13b and 130,provided in the opposed faces of the flanges 13 and 14, to provide aseal therebetween.

The ram sealing assembly (there being one disposed in each of thecylindrical housing portions 2 and 3), includes a deformable resilientsealing element 17 which has an elongated portion 17a with flat upperand lower sides terminated at the inner end, with substantially rightangular flanges 18 and 19 (see FIGURES II, V, and VI) Bolt receivingpassages 20 and 21 are provided through the flanges 18 and 19 for thepurposes hereinafter mentioned.

A semi-circular recess 23 is provided on the inner end of the extensionportion 17a, which is arranged to receive the polished rod 24, or othertubular or rod-like element, about which the ram sealing elements may besealed.

A top support plate 25 made of rigid material has a flat lower face 25aand a rounded upper face 25b, and a semi-circular recess 26 on the innerend thereof. The forward part of upper surface is sloped slightlyforward as indicated at 250 to facilitate the inward movement thereof.The top support plate is complementary to the ram sealing element 17 sothat when placed in the area between the flange 18 and the outer end ofthe extension portion 17a it will provide a continuous cylindricalsurface to fit within the circular bore of the body portions 2 and 3;and the recess 26 coincides with the recess 23.

Likewise, a bottom support plate 29 has a flat upper face 29a, a roundedlower face 29b and a semi-circular recess 30 on the outer end thereof.The bottom support plate 29 is complementary to the lower surface of theram sealing element 17 between the lower flange 19 and outer end of theportion 17a so that when assembled therewith it provides a continuouscylindrical surface for slidably fitting in the circular bores of theoutwardly extending portions 2 or 3 of the housing.

The circular ram back support plate 33 is made of rigid material and isarranged to abut against the rear side of the ram sealing element 17 andto slidably lit in the bores of the laterally extending portions 2 or 3of the housing.

The lower support plate 29 has a bore 32 therethrough which communicateswith an outer counterbore 31.

The pin 42 extends through the bore 32, counterbore 31, and passage 21of the sealing element 17. The pin 42 has a threaded end 43 thereonwhich is threadedly engaged with an interiorly threaded passage 37 inthe back support plate 33. The pin 42 has an enlarged head 44 thereonwhich engages the outer end of the bore 32 to limit longitudinalmovement therebetween.

The back support plate 33 has a passage 34 therethrough which isarranged to coincide with the passage 20 through the flange 18 of therubber sealing element 17, and with a bore 27 in the inner end of theupper support plate 25.

The bolt 39 extends through the aligned passages 34, 20 and 27, and hasa threaded end 40 thereon which may be threadedly engaged with thethreaded bore 28 in the inner end of the bore 27. The bolt 39 has anenlarged head 41 thereon, which is arranged to enter the counter- 4 bore35 at the outer end of the bore 34, and limits the longitudinal movementbetween the bolt 39 and the back support plate 33.

A slot 36, which is open at its lower end, is provided on the rear faceof the back support plate 33 and has an overhanging wall 38 about theouter side thereof, which provides a space 38a in which the head 46 ofthe feed screw may be inserted from the open end of the slot 36 toprovide a disengageable connection between the back plate 33 and thefeed screw 45.

The feed screw housing 47 is threadedly engaged at 45a about the feedscrew 45 and has an annular lip 45b on the inner end thereof which isslidably disposed with relation to the inner surface of the lateralhousing portions 2 or 3, as the case may be.

A gland 49 is slidably disposed in the outer end of the housing portions2 or 3 and about the feed screw housin 47.

The resilient packing rings 50 are clamped between the annular flange45b on the feed screw housing 47 and the inner end of the gland 49.

The gland 49 may be moved inwardly to compress the packing 50, by meansof a packing nut 51, is threadedly engaged about the threaded end 52 ofthe feed screw housing 47.

Packing rings 55 are disposed about the reduced diameter extension 48 ofthe feed screw 45, said packing rings 55 and end spacer rings 55a beingdisposed within a counterbore 47a provided in the outer end of the feedscrew housing 47, and are abutted against a shoulder 47b provided bysuch counterbore.

The packing 55 is retained in place by a gland 56 which may be movedinwardly against the spacer ring 55a to compress the packing 55 by meansof a gland nut 57 threadedly engaged about the outer end of the feedscrew housing 47.

A handle 58 is attached to the outer end of the feed screw 45 by meansof a pin which passes through the inner end of the handle and spacerring 59 disposed about the extension 48 and the pin 60 is securedthereto by means of the snap rings about the ends thereof.

It will be noted that there is a bore 62 extending entirely through thebolt 42 which provides communication between the counterbore 31 and thespace 63 at the rear of the ram assembly. Sufficient clearance isprovided between the lower inner side of the support plate 29 and thepolished rod 24 or other member about which the ram is disposed to allowcommunication between the area below the plate and counterbore 31.

The entire ram assembly, including the feed screw assembly, may beinserted in the lateral housing portions 2 or 3 and disengageablyattached therein by a U-shaped yoke 53, having spaced legs 53a thereon,which are arranged to pass through coinciding spaced passages 53b and53c in the wall of the housing portions 2 or 3 and through coincidingpassages (not shown) through the end plate 49. The yoke 53 may beretained in place by a retainer pin 54 passed through the ends thereof.

The operation and function of the device hereinbefore described is asfollows:

The ram is assembled in the manner shown in FIGURE I and inserted in theoutward extending housing portions 2 or 3, and is retained therein bythe yoke 53.

In order to move the sealing element 17 into sealing engagement aboutthe polished rod 24, or other rod-like or tubular element about which aseal is desired, the feed screw 45 is rotated by the handle 58, therebymoving it inwardly. Such rotation moves the back support plate 33inwardly, which in turn moves the sealing element 17, top support plate25 and bottom support plate 29 toward the polished rod 24.

After engagement of the inner surfaces of ram sealing elements 17 withthe polished rod 24, the continued forward movement of the back supportplate 33 will compress and move the ram sealing element around thepolished rod to provide a seal thereabout. The compression of thesealing element 17 also causes expansion outwardly to provide a sealwith the interior diameters of the housing portions 2 and 3.

As the seal 17 is expanded the pin 39 is permitted to move rearwardlythrough the bores 20 and 34; and the pin 42 is permitted to moveforwardly through the bores 32 and 21 and counterbore 31. Therefore, theupper sup port plate 25 and lower support plate 29 are allowed to movewith reference to the sealing element 17 as the sealing element is movedinwardly and expanded about the polished rod 24. Therefore, adequatesealing expansion is permitted about the member around which the sealingelements are sealed.

While the deformable sealing elements 17 are sealed about the member 24,it will be observed that pressure from below the sealing element ispermitted to pass through the passage 62 through bolt 42 to communicatewith the aera 63 behind the ram sealing assembly. Therefore, thepressure from below the ram sealing assembly assists in moving the raminwardly, and in maintaining it in sealing position. Any increasedpressure below the ram sealing assembly will act against the inner endthereof to further increase the seal between same and the polished rod24, or other element about which the seal is made.

The ram assembly may be replaced, or may be removed for replacement ofthe resilient sealing element 17 by simply loosening nut 51, removingthe yoke 53 and withdrawing same from the housing portion 2 or 3.

A ram sealing assembly, consisting of the resilient sealing element 17,top plate 25, bottom plate 29, back plate 33, and bolts 42 and 39 may beremoved from a ram assembly and replaced in its entirety by another sealassembly. Individual rubber sealing elements 17 may be quickly andeasily replac d in the sealing assembly by simply removing the bolts 39and 42 to disassemble the sealing element 17 from the plates 25, 29, and33.

Other and further embodiments of our invention may be devised withoutdeparting from the spirit and scope of the appended claims.

Having described our invention we claim:

1. The subcombination of a ram sealing assembly comprising a top plate,a lower plate, a back plate, a resilient sealing element disposedbetween the plates, the edges of the sealing element being exposedbetween the edges of said plates; a pin slidably extending through theback plate, the resilient sealing element and secured to the top plate;a pin slidably extending through the bottom plate, the resilient sealingelement and secured to the back plate; and, passage means extendingthrough said lower plate, sealing element, and back plate.

2. The subcombination called for in claim 1 wherein said passage meansincludes a passage extending through the last named pin.

References Cited UNITED STATES PATENTS 2,293,153 8/1942 Lorehn et al.277129- 2,760,749 8/1956 Ratigan 2.77129 X 2,877,977 3/1959 Allen 277129X SAMUEL ROTHBERG, Primary Examiner US. Cl. X.R. 277166

